This invention relates generally to rib-type metal roofs and relates more particularly to means for securing rib-type metal roofing panels to underlying structural members.
In a metal roof structure commonly referred to as a "rib" type, the edges of adjacent panels are placed in overlapping relationship, and the overlapped panels are secured to the structural members underlying the panels by appropriate securing means, such as self-tappinq sheet metal screws. Commonly, each panel of a rib-type metal roof is elongate in form and has a plurality of parallel ribs formed therein which run lengthwise of the panel. These panels, being metal, are known to experience dimensional changes, i.e., expansion and contraction, due to temperature variations to which the panels are exposed. In order to alleviate stresses and strains spawned by the expansion and contraction of the panels, devices or clips may be interposed between the panels of the roof and the underlying structural members for accommodating longitudinal dimensional changes in the panels. One such device is shown and described in U.S. Pat. 4,429,508.
It is an object of the present invention to provide a new and improved device of the aforedescribed class which accommodates longitudinal expansion and contraction of a rib-type roofing panel supported atop an underlying structural member.
Another object of the present invention is to provide such a device which is uncomplicated in construction and effective in operation.
Still another object of the present invention is to provide such a device which is well-suited for supporting a rib-type roofing panel above an existing rib-type roof.
A further object of the present invention is to provide a roofing system which incorporates such a device.